I bought these as an upgrade from the W3, which while extremely fun, I soon became disappointed in, due to mid bass bleed into the midrange. This caused vocals to become too chesty and distortion rock guitar notes too rounded instead of hard edged. Enter the W4.

Fit and Isolation: Westone 4 is extremely comfortable. I love their size and weight. They only fill up a small portion of the ear. On the downside the nozzle is very short, making them very tip dependent to achieve their great sound. Isolation is slightly above average with the right tip. Shure black olives work very well for best comfort but best sound is found in the old Shure e2c tips. They must be modded by using an olive core and provide the best bass response, without obscuring treble detail due to their larger sound hole opening.

Build Quality: Build quality is great. Westone has one of the best cables on the market. It is very flexible and light weight. It doesn’t tangle and is great for looping over the ear. The right angle connector fits most, if not all, iPhone cases including the bumper.

Accessories: Westone cases are one of the best on the market. The shape is small rectangle and perfect for fitting the phones and an iPod shuffle. Westone also provides a plethora of tips, none of which I like! Shure olives or modded Shure e2c soft flex tips are a must.

Sound: The W4’s are supremely balanced and natural. No one frequency intrudes on another. Detail retrieval is unparalleled. They are very smooth and coherent. The funny thing is you may not like them when you first put them in because there is no WOW factor. Once you get over that initial disappointment, they seemingly get better and better. The best compliment is to say they do nothing wrong.

Bass: Bass is well textured, detailed and controlled but could use a bit more sub bass presence and a tad more punch, mainly due to my preference for sleaze rock music. Don't mistake this for bass light; it is not.

Mids: Mids are perfect for me; just a tad forward and liquid. Vocals are placed perfectly.

Treble: Treble is amazingly extended without a hint of fatigue. Somehow Westone has developed an outstandingly detailed treble and at the same time velvety smooth. It’s very difficult to describe but very well done.

Soundstage: Soundstage is above average. The UE Triple.Fi 10 is the only IEM I own with a larger soundstage. However the TF10 makes you feel about 15 rows deep at a concert and the W4 seems to bring you closer, maybe to within 5 rows.

Overall the new W4’s find themselves at the top of BA universal heap, having Dynamic Driver quality timbre; Drums sound absolutely amazing on the W4. If you are looking for superb balance and refined detail retrieval, give the Westone 4 a try!

Somehow after using this W4 I notice that it is totally different sound to my UE700 :-| all of my musics sound like it was recorded on a cassette tape, I guess that because I need to use my W4 with FLAC or 320 kbps